1. Field of Invention
This invention relates to a collapsible backrest device, and particularly to a portable, collapsible backrest for use with a picnic table or other bench.
2. Description of the Relevant Art
There are known backrests. For example, Vieira U.S. Pat. No. 1,363,697 discloses a folding backrest for use in sitting on lawns, beaches, etc. The Vieira reference, however, fails to disclose a portable backrest which secures to a picnic table bench for use therewith.
Flanders U.S. Pat. No. 2,108,531 discloses a portable seat which is adapted for use with benches or bleachers, but provides limited space due to diagonal support bars 12 disposed on either side of the person seated in the seat, provides no adjustable backrest support when associated with a bench, and provides no resistance to forward movement of the seat.
Schafer U.S. Pat. No. 1,447,486 discloses a beach chair but fails to disclose a portable seat which attaches to a picnic table or bench plank.
Burgess U.S. Pat. No. 1,209,808 discloses a beach chair, but fails to disclose an adjustable backrest which securely attaches to a picnic table, bench, or bleacher.